Hydrogen cyanide-cobalt carbonyl reaction product



i. e;; with-the jcyan' group -attachufg toj Patented Jan. 19, 1 95 4 256 66.748 assassinations-cosine;chasm; REACTION PR DU T mington Belg Nemoui-swwco catibn Februaryfi} 1952F-Sei1ab d. 270524 m any, wilming ton,-i-l)elz',a. corl "mute" .7;

1 V 3'5 Thisinvention reiates' to at: znewixp preparing nitriles; by addition of'hydrog'em cy.-.- s

anidevtoi "olefinic bonds; and to new ioata'lystsffor carrying out: this sreactionr...

This:."application is a division of oursapplica-z-j. 5

tion: Serial Number- 137,481} filed flanua'ry 7;"19502 It isnknown thatfaddition-bf hydrogen cyanid to: activated double "bonds, i. V e.',- to ethylenic bonds" aadjacent'cto :a'n "activating group huch :as

the:nitri=le or 'acyl'oxy 3 groups; procee'ds-swith Ten-:-

tiverreaseizr On the 'otherhand dt -is -"extremely difli'cult ito addlhydrcgen cyanide *to a i doublebond':. in a mono =01 polyolefinic hydrocarbon f where 'no:' suchvactivating influence-: exists it? has been:- pointed ziouta'bye-Migrdichian in his re cent '1 book Chemistry of Organic Cyanogen Compounds? (A29 (3. S. Monogr-aph lOS; pagezlill that addition of" hydrogen cyanide to olefins'; if it proceeds 8111.311} requires ihigh' pressures} of the orderfof 1000 lbs. /sq;iin. orrmore, and high tamperatures" within-.:the zrangeiof" 200%00 C; Hy- V drogenwj cyanide?- addsl to conjugated diole'fins-= (which ihavefactivated double bondsh in 'fi the presence. of." =uprous chloride 'catalysts as de' scribed vfor example? in Uz S." Patents-2,422,859

and 2,44'73660; with production of '1 jl addition 5 products ::and :the so called norfiia L-Z add ti0n:. products,- t-i. .e.-; the'--; products wherein" the cyanoygroup isqattached toxthe carbon atom bear-ingtheleast number ofhydrogen-atoms: No'

instance has been reported of the so-"c'al-ledabf-" normalor :reverse? addition," i.e-, attachment of; thegcysmo group to :the 'carbon bearin'g' 'the mostxhydrogeni atoms'i This inventionshasaasan object the "additionFoi hydrogen cyanide toaethylenicbondsfi A- fu the'r object; is" the provision Zof. a process flopeiatin at? relatively. low temperatures =and 'at'- pressures as? low asthe autogenous pressure of theficeactants Another object is the addition of hydrogen cy nide to non-activated r: ethylenic -3 bond's such as are present 7' in 'monoolefinic' hydrocarbons?- A further object is aprocesqwhereby hydrogen cyanide is added marine n haying anv unsymlinkages conjugated, A -a se of hyd'rbeen if stillfurther object s These; objects: are accomplished. by thepfole lowing; invention wherein, an ethylenic "com-i: pound;zi.- ,e.;a compound having at least one care bonf-tolcarbon double bond which is ethylenic; i.;e:;,-nonearomaticgin; nature, is reacted withi'hye; drogem cyanide in: contact with a cobalt carbonyl catalystxi. 'e.;: ajcobalt: carbonyl per :se or. a .icom-Z plex-thereof-s Particularly, effectivezcobalt 'car-t V bonyl acom'plexesxare those formed by -reactioni of cobalt: ,carbonylgywithz; hydrogencyanide; These products are' new'fand {they-storm part f: thisin-vgentiomr The;-;ethy=1enic compound" and the hydrogen: cyanide aresuitably emp1oyed: Vin -approximately 5- equimolar -proportions:; butifw-desired-{either ree.

actant-y-canabe present {in-excess; which maybe; largeet; g.-, -2 to 110,: moles :vpermole; Howeven-c when: the *ethylenic 3 compound; is readily poly.- ii merizable 1: (for example; l,-3-butadiene)*' it mayo bepreferredmot-Y to use; anexcess of: it since; while a higher conversion of the-hydrogen cyan.

anide may be-obtained;-there may also be an increase in; the; formation: of polymeric residues.-

Thei catalysts;suitable for the process-of this invention are; cobalt 'carbonyl'icatalysts, i. e., the;

sts -mayponsist of a cobalt carbonyl cr -theyta may; comprise cobalt carbonyl; Thus, cobalt:

carbonyl itself may be used; themostzstable form r tricarbonyl may;be. usedrinstiead 20f. or in: addi= tion; to -cobalt tetra-carbonyl.

T here ;may;galso:be used as catalysts .the'icobalt J- carbonyl complexes which are the reaction prod ugts of -cobalt carbonyl with: hydrogen" cyanide.

ed; by 1 adding; cobalt tetracarbonyl to and reactslvithxit with evolution offi hy v ,drogen and carbon' monoxide; and deposition of 'a finely dividedblue-purplesolid; The solid -reaction proc luct;is;simi=lar.;in' appearance to cobal't cyanide; and; like cobalt 'cyanide it "dissolves 10%, agueous potassium cyanide solution" at roomete nperature, 4 and: the solution when h'eated gives potassium cobalti'cy'anide, KCMCNi; However, the cobalt. carbonyl hydrogen cyanide complexes are-quite different" analyticallyfrom cobaltycyanide: The latter-contains 53.1 %'-co ,ba1tand"25;2% nitrogen," whereas the cobalt These reactionproducts, which-have not here'- been described: in the chemical literature;

.7 v, ydros myanide at: any dcsired' tempera tulfe' between; about;-Q and about 200 C; The cobalt carbonyldissolves; in the hydrogen cy-' carbonyl-hydrogen cyanide complexes contain, depending upon the conditions of formation, from 23% to 44% cobalt and from 16% to 38% nitrogen. Moreover, on treatment with potassium cyanide solution to give, as already mentioned, potassium cobalt cyanide, the complexes evolve carbon monoxide, unlike cobalt cyanide. Cobalt cyanide is not a catalyst for the hydrocyanatioi'l of olefins, whereas the complexes just described are. It is possible that these compounds are formed in situ whenever an olefin is treated with hydrogen cyanide in the presence of cobalt carbonyl, but this has not been demonstrated.

Other suitable catalysts containing cobalt carbonyl are the heavy metal salts of cobalt carbonyl hydride (Z. Anorg. Chem., 232, 17 (1937)), for example, the mercury salt of cobalt carbonyl hydride, which has the formula Hg[Co(CO)4]z.

Further suitable catalysts are the cobalt carbonyl hydride-butadiene addition products described in application Serial Number 779,837, filed by Prichard on October 14, 1947, now Patent No. 2,600,571, issued June 17, 1952. These latter complexes are formed by reacting butadiene with cobalt carbonyl in the presence of a secondary alcohol and their probable molecular formula is C8H704CO. On the basis of present information, there may be used as catalyst in the process of this invention any material containing cobalt 1 carbonyl and in which the cobalt content is between about and The cobalt carbonyl catalyst is used in proportions, based on the ethylenic compound, between about 0.01 and 0.3 mole per mole, although more can be used if desired. A generally useful range is between 0.03 and 0.2 mole of catalyst per mole of unsaturate. Surprisingly, the free metal is ineffective in the hydrocyanation reaction at the low temperatures and pressures at which the cobalt carbonyl catalysts are eifective.

The reaction is preferably carried out in a substantially anhydrous medium although some water, for example the small amount (2-3%) present in commercial liquid hydrogen cyanide, I

is not usually detrimental. Even much larger amounts of water may be present but in such cases the conversion is in general sharply decreased. The highest conversions are observed when the hydrogen cyanide is at least partly dried, for example by passing it through a dehydrating agent, and also when the volatile acidic stabilizers sometimes present in it are at least partly removed, for example by bubbling nitrogen through the hydrogen cyanide for a few minutes.

,While the reaction takes place readily without addition of an extraneous solvent, it has been observed that better yields of nitrile sometimes result when the system comprises a solvent for the reactants and catalyst, probably because dilution tends to reduce the formation of polymers. Any aliphatically saturated organic liquid substantially inert towards reactants and catalysts may be used, in particular hydrocarbons such as benzene, toluene, hexane, cyclohexane, etc.; others, such as dipropyl ether, dibutyl ether, etc.; or other solvents such as tetrahydrofuran, etc. The solvent may be used in any desired proportions, such as between 0.5 mole and 10 moles or more based on the ethylenic compound.

The hydrocyanation reaction normally proceeds very slowly at low temperature, and to achieve a practical reaction rate it is generally desirable to operate above about C. The

- compose at relatively low temperature. It is possible that they are converted during the reaction to other cobalt derivatives having catalytic activity;

Since hydrogen cyanide boils at 26 C. and since the other reactants and solvents are in general volatile, it is necessary to operate in a closed, pressure-resistant vessel. Any suitable pressure vessel such as the conventional autoclaves or bombs, may be used. Reactors designed for continuous or semi-continuous operation may be used. For example, the cobalt carbonyl catalyst may be injected continuously under pressure into the reaction zone as a solution in an inert solvent such as benzene, the spent catalyst, which is in the form of a finely divided powder, may be filtered from the reaction prod not and any unreacted olefin and hydrogen cyanide recycled. If desired, agitation may be provided either internally or externally. The reaction proceeds at the autogenous pressure of the reactants and no additional pressure is necessary, although such may be used if desired. In this case, pressure may be provided by any inert gas such as nitrogen or air, or by an excess of a volatile unsaturate such as ethylene. Since the autogenous pressure of the reactants is not very high, it is unnecessary to use'equipment designed for extremely high pressures.

The reaction time depends upon several factors including the nature of t e unsaturate and the temperature. In general some nitrile will have formed within one or two hours at temperatures within the preferred range, i. e., above 0., and after 6 to 10 hours there is little further reaction and there is the danger of decomposing the reaction product. The nitrile or mixture of nitriles which form may be isolated by any suitable method such as direct distillation, steam distillation, crystallization if the nitriles are solid, etc. The unused hydrogen cyanide and ethylenic compound may be recovered and used again. As has already been mentioned, the cobalt carbonyl is decomposed, at least partly, during the reaction.

It has been observed that, in certain cases, the activity of the cobalt carbonyl catalysts may be enhanced by the presence in the reaction mixture of tertiary arylphosphines or arsines. The tertiary arylphosphine or arsine is desirably used in amounts of (Mil-0.3 mole, preferably 003-02 mole, per mole of insaturate. The influence of these promoters is shown in some of the examples.

The following examples in which parts are weight are illustrative of the invention.

EXAMPLE I A stainless steel reactor was charged with 40.5 parts of hydrogen cyanide, previously blown with nitrogen for two minutes and dried over calcium chloride, 86 parts of 1,3-butadiene and 17.1

parts of cobalt tetracarbonyl, C02(CO)a, these reactants being in the molar ratio of respectively. The tightness of the reactor was tested by pressuring with nitrogen and then venting to atmospheric pressure, leaving nitrogenas the gas above the reactants before sealing the een cyanide (i. bined with the cobalt), a higher conversion than waten, .-additional:water being. added as required.

The organic layer was separated fromtheaqueous distillate, driedover calcium chloride and fractionated. There wa-s obtained 14.4 parts of liquid boil-ineb wee r L; and 6 a mc ph ri p ssur n fll pfl i in Q T position to a pentenenitrile, i. e.-,, an. addition product. of; one moleof' hydrogen cyanide to one molaof; butadiene. Inaddition, there was. obtained 0..58:- Dotti-of higher boiling material hav ing a nitrogen content corresponding. tor the ormula qafieltae s heet 49 a undistillableresidue; including cobalt-containing; residues formed during the reaction. Comparison of the infrared absorption spectrogram of the 140146 C. fractionwith those of authentic spec mens of. 3x-penten nitri1eand 4-p tenen t this material was a; mixture oi nd: 23%... 4=pe tene it 1 rioecnkcnycrmen If is... noteworthy that. the. cobalt catalyst must bepresent," the. form, of, thev carbonyl compound td-promote-the. hydrocy anation reaction. There am hy ro en-cyanideaddition when the met itselfi is use as theicatal-yst in conjunction with car n mon xide, as shown; by t e: following on .eriment. Astainless steel reactor was charged with zfl parts of hydrogen cyanide, parts of 1.3 butadiene and. '25. parts of a. cobalt-onkieselguhr catalyst consisting of 25%. metal and %.hieselguhr. The reactor was pressured with nitrogen, vented, pressured; to 300j ..lb,s./sq. inwith carbon. monoxide... revented to atmospheric pressure, repressured to ZOlllbs/sq. in. of carbon monoxide-andsealed. The reaction charge was heated hour at so o, hour at 1,0,0. c. and finally- 9 hours. at 120. C. After coolingand venting steam distillation of the residue gave asthe sole reaction product. 2 parts of vinylc cl hex ne. o nitr enon a ning material was obtained.

EXAMPLE II A stainless steel reaction vessel was charged with-17.6 parts of cobalt tetracarbonyl, 55.5 parts or 133 butadiene, 27.8 parts of hydrogen cyanide (partly purified as in Example I) and 131.5. arts elf-benzene, pressured to 250 lbs/sq. with. ni trogen, then vented to atmospheric pressure. The reactor was heated at C. for /2 hour, at i009 C. for 3 hours, at C. for one hour and: finally at 140 C. for one hour, then cooled and: vented. The reaction product was steam distilledv and the organic layer was separated from the aqueous distillate and dried over calcium chloride. Fractionation yielded 24.2 parts ofimixed pentenenitriles boiling at 143.8-144.7 C; Infrared'spectrographic examination of this material. showed that it consisted of 73.5% of 3- pentenenitrile and 26.5% of'4pentenenitrile. In this experiment there was produced 0.37 mole of." pentenenitrile per available mole of hydroe., hydrogen cyanide not comthataobtained in the absence of solvent as in fixamplel. In addition, there was formed only 6.5.. parts of undistillable residue.

When a. similar experiment was run at lower temperaturelfiil" C. for 26 hours) the proportion methylglutaronitrile.

6.. oat-pentenenitrile thereaction ptQduct' was, increased; to 61%, as. calculated from. the. ins frared absorption spectro ram, theremaining, 39% being B-pentenenitrile. The conversion to. pentenenitriles was considerably lower at this temperature, however.

EXAMPLE" I11 Theiprocedure of. Example 11 was repeated one cent. that isopropyl. alcohol. was substituted. tor benzeneas the solvent. The reaction. product was. isolatedby filtering. the. charge removed from the bomb and iractionall y distilling filtrate. There was obtained. 16.6 partsoi mixed; pentenenitriles which contained 97%.. of, aspen tenenitrile and 31%. ofA-ipentenenitrile, as shown by infrared s oectrographicv examination. In ad: dition, there was obtained 0.6 part of a nitr en containing material. boiling at.l8.3.-184,? 0'0 mm. pressure, 32 1.4521, and.0;3.part of n trogen-containing material boilinsat llhl'ii. .4 at4mm.pressure,mzi'1.4723; 1

A. similar result, in that. the. reaction product consisted almost. exclusively of 3-pentenenitri1'e; was obtained whendiethyl ether was used as, the solvent, the. reactants. being in the same pros p io s s ab ve. andthe reaction. being carried out at 80 C. for. hour, then at. 1.0Q' C; for 5 /2 hours. There was obtained 717 narts of pen:

tenenitrile containing 97% of 3epentenenit le.

EXAMPLE A stainless steel reaction, vesself containing 103 01 hydrogen cyanide, 260- parts of p rified benzene, 162 parts of l,3'-butadiene and 51 parts of cobalt tetracarbonyl was heated for 14.5 hqnrs at C. under the autogenous' pressure of the reactants. The contents were rinsed out with benzene, filtered, and the filtrate was distilled. The products of several such runs were then worked up together by oareiul fractionation, and the fractions obtained were identified by infrared analysis and preparation of: suitable derivatives. The products. obtained and the, percent conversion" based on the but'adiene charged were as follows:

. Percent Vinylcyclohexene, ug w g,a 2-methyl-3 butenenitrile 3- pentenenitrile 4 penten ni r 1e 4;- Alpha, alpha-dimethyl succinonitr e. 3 Alpha?methylglutaronitrile. 12 P lym r i i. .q .-..-.i i i A stainless steel reactor. wascharged with 35.4

as shown by its boiling point 117 C. at 5 mm. pressure, its refractive index n 1.4316, and by comparison between its infrared-absorption spectrogram and that of an. authentic sample. of 2+.-

Nitrogen analysis (Kiel.-

7 dahl) gave 24.81% nitrogen as compared with the Calculated value 25.91%. Hydrolysis gave a compound analyzing correctly for Z-methylglutaric acid.

EXAMPLE VI A stainless steel reactor'was charged with 54 parts of hydrogen cyanide, 114 parts of butane-1, 17.1 parts of cobalt tetracarbonyl and 66 parts of benzene. The reactor was purged once with nitrogen, closed and raised to a temperature of 100 C. where it was maintained with agitation for 15 hours. The product was filtered and distilled and the portion boiling between 92 and 140 C. was refractionated. There was obtained 3.3 parts of valeronitrile boiling at 138-144 C. and having a refractive index n of 1.3922 to 1.4000.

Under somewhat different conditionsinvolving higher temperatures and absence of solvent, the addition of hydrogen cyanide to butene-l proceeds in the so-called normal manner, 1. e., It gives as the reaction product 2-methylbutyronitrile, \CH3CH(CN)CH2-CH3, rather than valerom'trile. For example, when 56 parts of 1- butene, 13.9 parts of hydrogen cyanide (the commercial product containing about 2.5% of water) and. 17v parts of cobalt tetracarbonyl were reacted for 8 hours at 130 0., there was obtained a 26.8% conversion of 2-methylbutyronitrile. This product when purified boiled at 126 C. and had a refractive index n 1.3882 and a specific gravity :1. 0.8063. It contained by analysis 16.06% nitrogen as compared with the calculated value, 16.9%.

The procedure just described but using carefully dried, stabilizer-free hydrogen cyanide prepared from sodium cyanide and sulfuric acid gave a 67.5% conversion to Z-methylbutyronitrile.

EXAMPLE VII A silver-lined pressure vessel was charged with 27 parts of hydrogen cyanide and 17 parts of cobalt tetracarbonyl. The vessel was pressured with 110 atmospheres of ethylene at 24 C. and heated for one hour each at 70 0., 80 (3., and 90 C. and finally for 7 hours at 100 0., in order to avoid the violent reaction experienced on raising the temperature too rapidly. The maximum pressure reached was 260 atmospheres at 80 C. and the final pressure was 195 atmospheres at 100 C. The reaction product was filtered from the catalyst and distilled. There was obtained 35 parts (64% conversion of the hydrogen cyanide) of propionitrile, B. P. 9698 C., n 1.3682.

EXAMPLE VIII A stainless steel reaction vessel was charged with 104 parts of freshly distilled styrene, 2 parts of hydroquinone, 17 parts of cobalt tetracarbonyl and 27 parts of hydrogen cyanide, and heated for 8 hours at 130 C. and 380355 lbs/sq. in. internal pressure. The vessel was then cooled, opened and the contents were rinsed out with benzene. After filtering off the spent catalyst, the filtrate was distilled and 68.5 parts (52.2% yield) of 2-pheny1pr0pionitrile, B. P. 117 C. at 20 mm. pressure, was isolated. It contained 10.79% nitrogen as compared with the calculated value of 10.7%.

EXAMPLE IX A stainless steel reactor was charged with 56 parts of butene-2, 13.5 parts of hydrogen cyanide, 17 parts of cobalt tetracarbonyl and 8.5 parts of triphenylphosphine, and heated for 9 hours at 130 C., the maximum pressure being 89 atmospheres. The product was filtered and distilled to give 17.8 parts (43% yield) of Z-methylbutyronitrile.

A similar experiment but without the triphenylphosphine gave a 9% yield of 2-methylbutyronitrile.

EXAMPLE X A silver-lined pressure vessel was charged with 41 parts of S-pentenenitrile, 27 parts of hydrogen cyanide, 17 parts of cobalt tetracarbonyl and 8.5 parts of triphenylphosphine and heated for 8 hours at 130 C. Working up of the reaction product gave 8.3 parts (15.4% yield) of Z-methyllutaronitrile.

A similar experiment but without the triphenylphosphine gave a 7% conversion to 2- methylglutaronitrile.

EXAMPLE XI A silver-lined reaction vessel was cooled in a carbon dioxide-acetone bath, flushed with nitro gen and charged with 17 parts of cobalt tetracarbonyl and 27 parts of hydrogen cyanide prepared from sodium cyanide and sulfuric acid and redistilled over phosphorus pentoxide. The vessel was then evacuated while in the cold bath and charged with 150 parts of propylene. Upon heating'the vessel to 130 C. the internal pressure rose to 110 atmospheres, then dropped to 90 atmospheres in one-half hour and remained there for 14.5 hours. The vessel was then cooled, opened, its contents rinsed out with ether, filtered and distilled. There was obtained 45 parts (65% conversion of hydrogen cyanide) of isobutyronitrile boiling at -105 0., n 1.372. Its nitrogen content was 19.86% as compared with the calculated value 20.3%.

When this experiment was repeated with addition of 8.5 parts of triphenylphosphine, the reaction flashed suddenly at a temperature of 70 C. to a temperature of 183 C. and a pressure of 300 atmospheres. The vessel was cooled to 130 C. and maintained there for 14.5 hours at a pressure of -100 atmospheres. There was recov- 1tiered 52 parts (75% conversion) of isobutyronirile.

EYLALEPLE XII A cobalt carbonyl-hydrogen cyanide complex was prepared as follows: A weighed amount of cobalt tetracarbonyl was added to hydrogen cyanide maintained at the refluxing temperature (26 C.) and the gases evolved were passed through a cold trap to remove the entrained hydrogen' cyanide and then through a dry test meter. The cobalt carbonyl was added overa one hour period, and the gas evolution continued for about 1 hours more. A total of 2.5 moles of gas was evolved per atom of cobalt in the cobalt carbonyl used. Gas samples were taken at intervals and analyzed in an Orsat apparatus. Only hydrogen and carbon monoxide were pres ent in appreciable amount (approximately in 1:4 ratio), the following gas sample being typical of the samples analyzed: carbon dioxide 0.2, unsaturate 1.0, oxygen 0.3, hydrogen 18.8, carbon monoxide 77.4, residual gas 2.2. 'The solid reaction product (cobalt carbonyl-hydrogen cyanide complex) was a blue powder containing 44.04% cobalt and 18.75% nitrogen which evolves carbon monoxide on treatment with aqueous potassium cyanide. A 13.5 part sample of this reaction product was placed in a pressure vessel asses-4s.

9. with 27 parts of hydrogen cyanide and 150 parts. of propylene. After 15 hours at. 1309 therewasv obtained 11 parts (15% conversion) of .150- butyronitrile.

Other cobalt. carbonyl-hydrogen cyanide complexes were prepared in the same manner, except that in one case the initial reaction temperature was2$ C. and no further external heat was applied and in another case the reaction temperature was C. Carbonmonoxide, and hydrogenwere evolved in s,ubstantial-ly the same. relative proportions. as. in the. above experiment. The reaction products were-again blue powders containing, respectively, 43.70% cobalt. and 1733595. nitrogen, and 13.20% cobalt. and- 13.72% nitrogen. When used as catalysts in the hydro cyanation of propylene, the conversion to isobutyronitrile was about with both products.

ExAMPr-a XIII cobalt. carbonyl-hydrogen cyanide complex was prepared as iollows: A stainless steel reaction vessel was charged with 8.3 parts of purified benzene, 25 parts of cobalt tetracarbonyl, and. ldzparts oi hydrogen cyanide. The vessel was pressured with 200 lbs/sq. in. of nitrogen and heated for 8 hours at 130 C. The pressure rose from 725 lbs/sq. in. at 130C. to 775 lbs/sq. in. 3 hours and rem ined there. or he rest f the run. When the vessel was cooled to room t mperature, the r sidu l pr ssure was 585 lbs ./sq, in indicating the loss of gas fromv the cobaltv carbonyl. The, contents of the vessel were rinsed out with benzene. The reaction product was a fine purple powder, insoluble in benzene, o ta n n 37. al and n ro en.

The cobalt carbonyl-hydrogen cyanide com plex isolated above was placed in a si'lver 'lined reactor with 27 parts of hydrogen cyanide and 150 parts of propylene. During the first. .4 hours at. .130. C... the pressure dropped from, 2.90 to. 2.1.5 atmospheres. Aiter .15 hours the. pressure. was 21.0. atmospheres. There. was obtained .29. parts .(42% conversion of hydrogen cyanide.) of isobutyronitrila noatalyst h ving similar activity was pro uced 'by reacting cobalt tetracarbonyl with hydrogen cyanide at 160 C. in'furan as solvent. This complexcontained 23.65% cobalt and 37.73% trosen.

EXAMPLE XIV .A mixture of 56. parts of buteneu, 13.5 parts or hydrogen-cyanide and .7 par s or cobalt tetrahydro en cyan de in the. second run, giving a product. higher in nitrogen content and lower in cobalt content.

XAMPLE. X

- a silver linedp essure essel arsed-with of t -mercury sal of oohaltgoarbonrl 10 hydride, 5.0 parts or" hydro n oyanide and .175 parts of propylene. and heated at 130 C. for 1 5 hours. The pressure dropped from a maximum of 275 atmospheres to 1.00 tm s h n two hours. There was recovered 79 parts (63.1% yield) of isobutyronitrile.

The mercury salt of cobalt carbonyl hydride used in this and the following example was prepared as follows:

Twenty-five parts of finely divided cobalt, metal, 57.5 parts of mercuric chloride, 27 parts of copper powder and 71.3 parts of anhydrous ether were charged into a copper-lined pressure vessel which had previously been swept free of oxygen by means. of a stream of dry nitrogen. The vessel was adjusted to maintain a pressure of 1000 atmospheres. of carbon monoxideand heated for one hour at 150 (2., one hour at160 C. and ten hours at 170 C. The reaction product was extracted three'times with parts of ether. then the solid residue was extracted three times with 50 parts of methylene chloride. The ether and methylene chloride extracts gave 27 and 31 parts, respectively. of the mercuric salt of cobalt carbonyl hydride, the total yield being 52% of the theoretical.

Analysis Calculated for .Hg[CO C;O;)4]2Z Hg, 38.0%; Co,

21.76%; C, 17.71%. Found: Hg, 37.00%; Co, 21.76%; C, 17.73%.

The mercuric salt of cobalt carbonyl hydride is a bright orange-yellow solid, stable in air, and

EXAMPLE XVI ,A stainless steel reaction vessel was cooled and charged with 27' parts of hydrogen cyanide, 55.2 parts of 1,.3-hl1tadiene, 27.1 parts of the mercuric salt of cobalt carbonyl hydride and 132 parts of benzene. The vessel Was closed and heated und r aut enous. press re. at .0- r /z h at C. f r hours, at C. for one ho r and at &0 C. for one hour- The action produc was filtered to remove the solid resid e. which was washed with -5 parts of benz ne. The combined benzene solu o s were .fra na l distilled to yield .8 pa ts of a materi ling at 112-138" C. which contained Z-methyl-S-butenenitrile, 35 parts of a mixture of 3-pentenenitrile and 4-pentenenitrile, and 7.9 parts of higher boiling nitriles which contained 2.9 parts. of Z-methylglutaronitrile. The mixture of pentenenitrile was shown by infrared spectrograms to comprise 25% of d-pentenenitrile and 75% of 3-pentenenitrile.

ButadieneAcobalt carbonyl hydride was prea ed as desc ibed in pp ication Serial No- 77.9,8 37. already referred to. by heatin cobalt carbonyl and isopropanol at .C. under 100 atmospheres carbon monoxide pressure while injecting 1,3-butadiene continuously. The product was isolated as a liquid boiling at 32-33 C. at 2 pressure.

Astainless steel reaction vessel was charged with. 4.6 parts. of butadiene/icobalt carbonyl hydride; 56.8 parts of '1, 3,-butadicne, 27 parts of EXAMPLE XVIII A stainless steel bomb was charged with 56 parts of cctene-l, 17 parts of cobalt tetracarbonyl, 8.5 parts of triphenylphosphine and 27 parts of hydrogen cyanide and heated for 8 hours at 130 C., the maximum pressure reached being 650 lbs/sq. in. The contents of the bomb were rinsed out with ether, filtered and distilled. There was obtained 16.5 parts (23.7% yield) of alpha-methylcaprylonitrile, B. P. 209 C. at 751 mm. pressure, n 1.4181.

Analysis Calculated for C9H17N: C, 77.7%; H, 12.2%; N,

Found: C, 77.6%, 77.3%; H, 11.6%, 11.7%; N,

EXAMPLE XIX A stainless steel pressure vessel was charged with 22 parts of methyl -hexenoate, 27 parts of hydrogen cyanide and 17 parts of cobalt tetracarbonyl and heated at 130 C. for 8 hours, the maximum pressure being 28 atmospheres. Distillation of the product after filtering off the spent catalyst gave 4.9 parts (19.3% conversion) of a mole for mole hydrogen cyanide adduct of the formula CsHisOaN.

Analysis Calculated for CsHnOzN: C, 61.9%; H, 8.4%;

N, 9.05%. Found: C, 61.85%; H, 8.70%; N, 8.77%.

EXAMPLE XX A stainless steel bomb was charged with 19 parts of 5-hexenenitrile, 17 parts of cobalt tetracarbonyl and 27 parts of hydrogen cyanide and heated for 8 hours at 130 C. After filtering and distilling the product, there was obtained 8.7 parts (35.6% conversion) of a dinitrile of formula C'lHlONz, n 1.4348, which was probably alphamethyladiponitrile.

Analysis Calculated for C'IH10N2I N, 22.9%. Found: N, 22.7%.

The 5-hexenenitrile used in this example was prepared according to the general disclosure of application Serial No. 101,905, filed on June 28, 1949, by Albisetti and Fisher, by heating a mixture of 50 parts of acrylonitrile and 200 parts of propylene for four hours at 240 C. and 1000 atmospheres pressure. Distillation of the reaction product gave 5-hexenenitrile, B. P. 162 C. at atmospheric pressure.

EXAMPLE XXI A stainless steel reactor was charged with 68 Parts of isoprene, 88 parts of benzene, 17 parts of cobalt tetracarbonyl and 27 parts of hydrogen cyanide and heated at 130 C. for 18.5 hours, the

maximum pressure being 725 lbs/sq. in. The contents of the reactor were rinsed out with benzene, filtered and distilled. There was obtained 48 parts (50.5% yield) of a mononitrile which upon careful fractionation was found to consist of of 4-methyl-3-pentenenitrile and 25% of 3-methyl-3-pentenenitrile. The first one had a boiling point of 165 C. and a refractive index n of 1.4330. It was further identified by infrared analysis and by hydrogenation and hydrolysis to 4-methylpentanoic acid. The second one, which apparently formed a constant boiling mixture with the dimer of isoprene which also formed, was identified by infrared analysis and by hydrogenation and hydrolysis to B-methylpentanoic acid.

EXAMPLE XECCI A stainless steel bomb was charged with 27 parts of hydrogen cyanide, 17 parts of cobalt tetracarbonyl, and 54 parts of vinylcyclohexene (the dimer of 1,3-butadiene) and heated at C. for 19.5 hours, the pressure being 700675 lbs./ sq. in. There was obtained 9.5 parts (14.1%

' yield) of the mononitrile, alpha-methyl-3-cyclohexene-l-acetonitrile.

' Analysis Calculated for CsHiaNz C, 80.0%; H, 9.6%; N,

10.4%. Found: C, 79.48%; H, 9.89%; N, 10.36%.

The product was further identified by hydrogenation of the double bond, followed by hydrolysis to an acid identical, by mixed melting point, with the acid obtained by hydrogenation of the aromatic ring in an authentic sample of hydratropic acid.

EXAMPLE XXIII A stainless steel reactor was charged with 41 parts of biallyl, 27 parts of hydrogen cyanide and 17 parts of cobalt tetracarbonyl and heated for 8 hours at 130 C. There was obtained 12.7 parts of a mononitrile fraction, B. P. -l60 C. at 760 mm. pressure, and 5.2 parts of a dinitrile fraction, B. P. 130-150 C. at 20 mm. pressure.

EXAMPLE XXIV A stainless steel reactor was charged with .60 parts of dicyclopentadiene, 27 parts of hydrogen cyanide, 8.5 parts of triphenylphosphine and 17 parts of cobalt tetracarbonyl and heated at 130 C. for 15.5 hours, the pressure being 660-625 lbs/sq. in. There was obtained 17.4 parts (24% yield) of a mononitrile having the formula CiiHisN.

Analysis Calculated for CnHiaN: N, 8.8%. Found: N, 8.5%.

EXAMPLE XXV Bicyclo [2.2.1] -5-heptene-2-carbonitrile,,.was prepared by condensing cyclopentadiene with acrylonitrile (see Bruson, J. Chem. Soc. 64, 2457-61, (1942)). A stainless steel reactor was charged with 167 parts or bicyclo [2.2.1l-5-heptene-Z-carbonitrile', 54 parts of hydrogen cy' anide, 51 parts of cobalt tetracarbonyl and 25 parts of triphenylpho 'sphine and heated for 8 hours at 130 C. There was recovered 30 parts starting material 2116.126 parts (62% conver- "of a dii'ii tril'e 'wnienwas a semi-send at room temperature. This 'W'asa mixtureof position and/or geometrical iso ers. A solid and a liquid fraction wer bbtaineq by fi tration and (both analysed correctly for 2,5 (or '6)-"'norca;'m-

phanedicarbonitrile,

(the hydrogen atoms on the left side of the formula here and below have been omitted to indicate that the position of the cyano group is I not known).

Analysis Calculated for C'eHmNz: C, 74.0%; H, 6.8%; N,

19.2%; mol. wt, 146.

Found (on liquid fraction) C, 74.32% H, 6.7 1%;

N, 18.16%; mol. 151, 145.

On catalytic hydrogenation at 125 C. and

1800-2000 lbs/sq. in. hydrogen pressure in the presence of anhydrous ammonia and Raney cobalt catalyst, either the liquid or the solid fraction or their mixture gives 2,5 (or 6) -di(aminomethyl) norcamphane on-omunl EXAMPLE XXVI /CH no onc=o CH. HO 1 (IE-0:0

Bicyclo [2.2.1]-5-heptene-2,3-dicarboxylic anhydride was prepared by reacting maleic anhydride with oyclopentadiene (Diels and Alder, Ann. 460, 98-122 (1928)). A stainless steel pressure vessel was charged with 164 parts of bicyclo [2.2.1]-5-heptene-2,3-dicarboxylic anhydride, 54 parts of hydrogen cyanide, 17 parts of cobalt tetracarbonyl and 20 parts of triphenylphosphine and heated for 8 hours at C. There was obtained 54 parts (28% conversion) of a high boiling syrup which upon two recrystallizations from a toluene-xylene mixture, gave a mixture of isomers melting at -167" C. This mixture had a composition corresponding to 5 (or.;6)-cyano-bicyclo [2.2.1] heptane-2,3--di carboxylic anhydride.

Analysis N, 7.3%. Found: C, 63.17%; H, 4.99%; N, 7.81%.

in the resets of this invention there may be employed other unsaturated compounds having one --or more carbon-to carbon double bonds aliphatic in character. In addition to the compounds uses in "the esainpies theremay be mentiorre'd, as suitable unsatu'rates, pentene l fp'endefile-2, serene-1, -hexene-3, alpha-methyl .ta-

'diehe, allylbenzene, dcdece'ne-l, hexadecer-red,

octadecene-l, vinylnaphthalene and the like. The process is applicable to unsaturated compounds having substituents such as nitrile, halogen, hydroxyl, alkoxy, carboxy, etc., particularly in cases where these substituents are more than one carbon removed from the double bond, i. e., are isolated or independen and thus exert no activating influence. However, the special usefulness of the process lies in its application to ethylenic hydrocarbons since this class of compounds is particularly resistant to hydrocyanation by the methods heretofore known, and to ethylenically unsaturated aliphatic or cycloaliphatic nitriles where the double bond is more than one carbon removed from the cyano group, and in particular to unsaturated hydrocarbons or nitriles having a maximum of 12 carbon atoms. A specifically useful embodiment of the invention is the hydrocyanation of unsaturated hydrocarbons of 2 to 12 carbon atoms in which the aliphatic unsaturation is only ethylenic and is in an open chain, and in which each of the ethylenically bonded carbons bears at least one hydrogen atom. Olefins having a doubly bonded carbon free from hydrogen, e. g., isobutene, are not preferred, since the addition product is formed in less advantageous amount and tends to be polymeric. A specific and important use of the process is the hydrocyanation with cobalt carbonyl of 1,3-butadiene since the resulting nitriles may be converted to acids or amines for use as intermediates in the synthesis of polyamides.

As shown in some of the examples, it is sometimes possible under certain conditions to direct the reaction so that addition of hydrogen cyanide takes place contrary to Markownikofis rule. While it is not possible to lay down precise rules as to how this can be accomplished, it appears that abnormal or reverse addition of hydrogen cyanide is favored by low temperatures and the presence of benzene as the diluent.

The cobalt carbonyl/hydrogen cyanide adducts described herein are useful, as already disclosed, as hydrocyanation catalysts. obtainable by this process are useful as chemical intermediates in the synthesis of acids, amines, amides, polyamidcs, etc. They are also useful per se as insecticides, fumigants, solvents, etc.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations are to be understood therefrom. The invention is not limited to the exact details shown and described for obvious modifications will occur to those skilled in the art.

What is claimed is:

A product of the reaction, at 0-200 C., oi anhydrous hydrogen cyanide with cobalt carbonyl, Ioz(CO)a, said product being blue-purple in color, of 23-44% cobalt content and 16-38% The nitriles nitrogen content, soluble in aqueous potassium cyanide solution with the evolution of carbon monoxide to an aqueous solution which on heating gives potassium cobalticyanide.

PAUL ARTHUR, JR.

BURT CARLTON PRATT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,385,741 Teter Sept. 25, 1945 Harris Dec. 14, 1948 16 OTHER REFERENCES 

